Dead front safety panel



March 10. 1925. 1,529,484

G. w. HYSER DEAD FRONTQAFETY PANEL 0 v Filed Jan. 5, 1921 2 Sheets-Sheet1 fm/erzzor 6,6075% VJ 133 5 67' 9 M 7125 Af Q N LANG Liv (OI I T M 1 fiF m March 10. 1925. v

G. w. HYSER V DEAD FRONT SAFETY PANEL;

m m w m G Wm. [m w 2 F F W Big;

Patented Mar. 10, 1925.

UNITED STATES GEORGE W-. OF MINNEAPOLIS; MINNESOTA.

.nnnn mom sarmy PANEL Application filed Janus-r13, 1 921.

citizen of the United States, resident'ot Minneapolis, county ofHennepin, State of Minnesota, have invented certain new andusefulImprovements 1n Dead Front Safety-f- Panels, o't which the following isaispecification.

My invention relateslto cabinets wherein circuit switches, fuse cups andother electric connections are mounted and the object of the inventionis to provide a COIlStlllCtlOIl:

A further object is to eliminate the use .of'

fuse cups and switches of special construction and also the polishingand finishing of all bus and branch bars;

A further and particular object isto provide a construction which willmake it possible to remove either fuse cup or switch. from the panelwithout disturbing any of..- the steel plates, bus bars, or any otherpartv of the equipment, and, further, .to provide a panel of simpleinexpensive construction and one which can not be derangedor inad?vertently damaged by a person unfamiliar with devices of thiskind.

The invention consists generally in various constructionsandcombinationsaall as hereinafter described and particularly pointed outin the claims.

In the accompanying drawings forming part of this specification,

Figure l is a front elevation of a portion of a cabinet with myinvention embodied therein;

Figure 2 is a horizontal sectional view on the line 2-2 of Figure 1.

Figure 3 is a rear view of the panel removed from the cabinet to showthe bus bar connection thereon;

Figure 4 is a cross sectional view on the line 44: of Figure 3;

Figure 5 is a similar view on the line 55 of Figure 3.

In the drawings, 2 represents the rear wall of the cabinet and 3 theside walls formed preferably by folding outwardly the edges Serial in.434,547.

ofa-the sheet steel plate of which the rear wall 2is composed and 4 isthe front of the cabinet, secured by suitable means to theinwardly-turned flanged edges 5 of the side walls. In this style ofcabinet front I provide-a single door Gthrough which access is had'tothe interior of the cabinet and the mechanism contained therein. Whenswitches are employed in the circuit two doors will beprovidedlin thefront of the cabinet. arrangement of doors, however,-isrnot novel, and Imake no claim to such construction herein. 7 represents the sheetoffinsulrating material which I prefer to place against the rear wall ofthe cabinet andinthe rear of the bus bars and other, apparatus whichwill presentlybe described in detail. 8 is a yoke having end portions 9securedto the rear wall of the cabinet by suitable means, such as screws10 and on this yoke the insulating plateor element 11, preferably ofslate, usuallylused in cabinets of this kind, is mounted; A space 12 isprovided between the plate 11 and the rear wall of the cabinet and inthis space I arrange the potential bus bars 13 separated by air gapsfrom the walls of the cabinet and from the yoke 8. The neutral bus bar13 is arranged between the other' bars and seated on a branch bar 1'3which connects the opposite fuse cups and is preferably seated on theback of the insulatingcelement. Ordinarily these bus bars arearrangedinfront of the plate whereon' the fuse on s are mounted and-aste'elplate is arrangec in front of the bus bars. Such construction isobjectionable, as itincreases the expense of the device, the steelplate, while normally dead, is-liable to become charged from one of theswitches in the rear of the plate so that an operator or attendant mayreceive a severe shock while working around the cabinet. By locating thebus bars in the rear of the plate 11 where they cannot be seen, orreached by the ordinary observer or attendant, I eliminate all danger ofcharging any of the conductors with which the hands of an attendant maycome in contact and furthermore, the bus bars are not particularlyornamental and the appearance of the cabinet is greatly enhanced byconcealing them in the rear of the insulating plate of slate 11.

The outer bus bars 13 are secured to the backfof the plate 11 by meansof suitable screws 14, and are preferably spaced therefrom by suitablespacing collars 14: asshown in Figure 4. These two bus bars are e'lectrically' connected to the fuse cups 16 (of cups l6 by means of thebranch bars 13" and screws in as shown in Fig. 5. A connecting screw 15is also provided in each fuse cup, and these screws have their lowerends suitably secured to a series of connect-' ing bars 17 which havetheir outer ends in electrical connection with the binding posts 18. In'F 1g. 3, there is shown a panel having four branch circuits, eachcircuit comprising in the cups-16 and 16 of a circuit, such circuit Wlllbe closed between the bus bars and of panel and el tends outwardly fromthe plate 11 to a point near the front wall of the cabinet and preventstheattendant from inserting his hand into the space between the plate 11and the front of the cabinet and coming in contact with the terminals 18or with any other charged part of the apparatus. When switches areemployed in the circuits the insulating wall incloses the switches only.

In various ways the details of construetion herein shown and. describedmaybe modified and still be within the scope of my invention, theessential feature of which consists in providing the insulating plate infrontof the bus and bars thereby protecting theperson working around thecabinet from injury. V T

I'claim as my invention:

1. The combination, with a cabinet, of an insulating plate mountedtherein and spaced from the rear wall of the cabinet, bus bars arrangedin the space betweensaid rear wall and said insulating platey fuse' cupsmounted on the front of said insulating- The central bus bar 13 iselectri plate and in circuit with said bus bars, termm'als for said busbars mounted in the outer portions of said insulating plate, andinsulating wall encircling said fuse cups and separating them from saidterminals.

2.1'The combination, with a cabinet, of an insulating plate mountedtherein, bus bars arranged in the rear of said insulating plate andnormally concealed thereby, terminals,

for said bus bars mounted in said insulating plate, fuse cups mounted onthe front of said.

insulating plate and in circu t with said bus. bars and a wall withinsaid cablnet 1nterposed between said terminals and said fuse cups andclosing the gap around sald cups 7 w a j and between them and saidterminals. two fuse cups l6 and 16?. Thus, 1t w1ll' readily be seen thatwhen fuse plugs are inserted 3. The combination with a cabinet having afront wall and a door opening therein and .ado'or therefor, of aninsulating element mo'untedin said cabinet in the rear of said bindingposts 18. A wall of either slate or steel 19 encircles the fuse cups inthis-type,

door opening and opposite the same, bus

bars mounted in the rear of said insulatingelement, terminals thereformounted on said insulating element, fuse cups mounted on .saidinsulating element and connected with hand reaching through said dooropening from contacting with said terminals.

t. The combination, with a cabinet having a front wall and a dooropening therein and doortherefor, of an insulating plate mounted insaid-cabinet in the rear of said door opening and opposite the same, busbars.

.mounted in the rear of said plate, terminals therefor mounted on saidplate, fuse cups.

mounted on said plate and connected with V saidbus bars and a wallseparating said ter- -m1-nals from sa d fuse cups and prqectmg outwardlyfrom said plate to a point near said door opening and preventing accessto said terminals through said opening.

Injwitness whereof, I have hereunto set my hand this 29" day ofDecember, 1920.

' GEO. VV..HYSER..

